have seen a lot of interest in freeing up frozen motors. heat gun ,crock pot .all good BUT i find that in most older engines that are frozen ( especially Super Tigres the rod will be stuck on the wrist pin and if not freed up wi ll wear out the piston wrist pin hole .it the rod need to be freed up .if u are having trouble getting the piston off of the crank pin it is probly because the rod is frozen on the pin and will not move far enough to get rod off the crank pin . a little extra time here will show up in the long run .RAD

I've started going through all of my better engines, most of which haven't been used for years, and the first thing I do is to remove the backplate and check that the rod moves along the wristpin. If not then I invert the engine and flood the inside of the piston with acetone so it covers the wristpin area then, using whatever method you like, apply force to the top of the rod to get it to start moving in both directions to allow the acetone to begin wicking through the rod clearance. It's surprising how little movement is needed to get things going, my guess is even .001" or .002" is sufficient, but from there on things get better very quickly.

I have way too many engines sitting on shelves that don't get moved for a few years at a time and so indeed get a number of them stuck.   I've taken to simply putting a few stuck ones on a cookie sheet and roasting the whole thing in the oven at about 200 degrees for 30 minutes or so.   In most cases this emulsifies the congealed oil, then I put on a prop and turn them over with a shot of Marvel's Mystery Oil.  Good to go back on the shelf usually without needing to take them apart.  Works 95% of the time.   This temp is safe-they can get much hotter running.   If they happen to have a plastic venturi you might consider removing that.  Not had any issues with nylon though.

Dave

Marvel Mystery oil will frequently gum up after a few years. Marvel (or other brand) air tool oil is much more reliable.  It will stay good for at least 10 years.

   For assembly, I use Singer light machine oil, except for the wrist pin, where I use 3-in-1 *motor oil* intended for 1/4 horse or larger electric motors (not regular 3-in-1), air tool oil, or even Mobil 1 0w-20. I have some of my Dads engines put together with sewing machine oil that are as loose as the day he put them away 50ish years ago.

      To be honest, I have not routinely used after-run oil for about 20 years now, and have had nearly zero bearing issues caused by wear. Bearings *chipping* is another issue, the rear bearing on the Jett is one the edge of too small for the rather extreme loads, particularly with my setup. They don't seem to wear out, but are marginal to take the pounding. The OD is good-sized, but the crankshaft/ ID is also huge, so the bearing itself is pretty thin. Biggest issue is the chip tearing up the liner on the way out.

      Brett

The stoirey on dem stalkers and dat castor ;

Out over theway , way back when . Castor had some oil in it , as a rule . whereas this new stuff , you never new what you were getting . So you got castor and knew . even if you didnt really .

Cheap C had soot & gunge . but   L U B R I C A T E D . Whereas synthetic has a ' Fllash Point ' where it suffers spontaeousl combustion . About 650 deg. And theres nothing left .

As a result , modern Syn. is fine . But a lot run 50 / 50 .  Batman says Motul Micro 2T is essential for the Retro , to prevent a stumble . Which is $ 100 Aus. a litre . ( these Americans dont know how good theyve got it )
So , we dont know how THAT compares to your Mobil Jet Oil ; which is what brought all this on .

Oweva , as Assembly Oil - for storage : Chainsaw Bar Oil & motorcycle Chain Oil , are sticky .

" WD-40 300g Specialist Rust Prevention Lanolin " saw just the other day . And READ just last Knight " WD - 40 secrets list aerospace blah scientist blah , just released . Publicly . 1965ish ' Motor Sport ' ( with real cars init )

THEM THERE Wrist Pins , Quite Often a rich sooty old idled coked up Ex RC motor , The Wrist Pin has donuts of castor twixt rod & piston. and theyve SET . Hard . and DONT want to Disolve ! which can be annoying .
Dry Nitro Corroded ones , Ferrous / Oxide  , here & there Both . Rod . and Piston. Particulary . Can Be An issue . ussually two weeks of heating and spraying with C R C / WD 40 might free it off . or start to . if youlucky .

The EsasyOut , if you dont break it , might get the W Pin spinniing . Which is a start . then you find the 4.000.000 brinel hardness castor rings up inside it there . So you sit it upside down with the piston full of
acetone , then CRC , then oven cleaner . Brake Cleaner. Carb Cleaner .petrol . and anything else you can think off . alternately . overnight . or longer .

Best flush the stalkers and Oil with sumint Potent . before shelving them . even when using no nitro . stored low over concrette seems worset .

The stoirey on dem stalkers and dat castor ;

So , we dont know how THAT compares to your Mobil Jet Oil ; which is what brought all this on .

Chainsaw Bar Oil & motorcycle Chain Oil , are sticky .

" WD-40 300g Specialist Rust Prevention Lanolin " saw just the other day.

Matt, I'm having trouble with your fractured English but I'll try to answer as best as possible.
Regarding the Jet oil, I'm an ex aircraft engine fitter (21+ years) working mainly on Jindiviks, Canberras and F-111's so I've handled Mobil Jet Oil II all that time. Because the oil is contained in the engine gearbox it has to handle very high temperatures as well as the extreme pressures lubricating all the gears while keeping them free from any rusting during down times. It's also used in the F-III's massive generators. Essentially the oil is a MIL spec version of an ATF.

Chainsaw bar oil, sticky. Yes, very sticky but there's a very cheap alternative that even some professional lumberjacks use. Pop down to your local Foodland and buy a 2 litre bottle of Canola oil. I use it in my small chainsaw.

Rust prevention lanolin. Gordon Burford used lanolin in his engines before boxing them up. Pop down to your local Bunnings and get a tin of inox MX4 Lanox spray can of lanolin. It's quite cheap.

Lanolin....baaaah!  Steve

I am not sure what problems we are trying to solve with sheep sweat.   All that is required is some sort of oil that does not gum up over time, and doesn't ruin the glow plug when you do finally go to run it. Any quality mineral oil - that is, actual oil, and not thinned-out wax, not Marvel Mystery Oil, 3 in 1, WD-40, etc, but plain old oil like *mineral* motor oil, etc. will keep out the rust sufficiently. Lots of stuff works about equally well - Rislone, *mineral* ATF, any mineral motor oil, air tool oil, sewing machine oil and stuff like that. You probably don't want silicone-based anything, synthetic, etc, just because you eventually plan on running the engine and that stuff might - not sure, but might - coat the plug or create a tater on the way out.

    I like the sewing machine oil because it does the job and starts out and stays thin enough that you don't have to do much to loosen it up when you do finally go to run it, unlike a lot of other much thicker oil. Air tool oil is thicker and takes about half a flight to go away completely, you can smell it in the exhaust.

      I have had the *idea* of taking engines and storing them in a jar of rislone or ATF (or now maybe jet oil). But doing it the way I am doing it is good enough.

     Brett